A single cervical length measurement at 18–24 weeks is a better predictor of preterm birth than the change in cervical length with gestation

Commentary on : Conde-Agudelo A, Romero R. Predictive accuracy of changes in transvaginal sonographic cervical length over time for preterm birth: a systematic review and meta-analysis. Am J Obstet Gynecol 2015. Published Online First. Transvaginally measured cervical length (CL) at 18–24 weeks’ gestation is a strong predictor of preterm birth (PTB) in asymptomatic women, regardless of their prior risk.1 ,2 The association between shortening of the CL over time and the risk of PTB is controversial.3 ,4 This systematic review and meta-analysis investigates the predictive accuracy of changes in CL with gestation in quantifying the risk of PTB. This was a review of cohort or cross-sectional studies which allowed construction of 2×2 contingency tables, investigating the accuracy of serial transvaginal CL in predicting PTB in asymptomatic women. The outcomes included PTB at <32, <34, <35 and <37 weeks. The review excluded …